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TERRESTRIAL SEQUENSTARTION - Coggle Diagram
TERRESTRIAL SEQUENSTARTION
PRIMARY PRODUCERS
Primary producers sequester carbon through the process of photosynthesis. All living things either release or intake carbon.
▪ Primary producers (plants) take carbon from the atmosphere to photosynthesise and release carbon when they respire.
▪ Vegetation growth depends on water, nutrients and sunlight.
CONDUMERS eat plants, carbon from the plants is converted into fats and proteins.
MICRO ORGANISM feed on waste material from animals and plants.
DECOMPOSITION Animal and plant remains are easier to decompose compared to wood. Decomposition is faster in tropical climates with high rainfall, temperatures and oxygen levels.
TREE BIOMASS
95% of a tree’s biomass consists of CO2 which is sequestered and converted to cellulose. The amount of carbon stored in trees depends on the balance of respiration and photosynthesis.
VARIATIONS
Diurnally – during the day, fluxes are positive from the atmosphere to the ecosyste
Seasonally – In the northern hemisphere during winter, plants die and decay leading to high atmospheric CO2 concentrations but during spring when plants begin to grow, CO2 levels in the atmosphere begin to drop.
CHNAGES IN FORESTS
forests are declining in the tropical areas in the southern hemisphere and growing in the northern hemisphere . This is supported by data which shows that tropical areas such as Brazil and Indonesia have seen a decrease in carbon stocks of around 5 Gigatons of Carbon (GtC) in the last 25 years , but Russia, USA and China have seen increases of around 0.3, 2.9 and 2.3 GtC respectively.
● Non-tropical forests have seen an increase in carbon sequestration in recent years, especially in Europe and Eastern Asia, due to conversion of agricultural land and plantations to new forests.
● Forests in industrialised regions are expected to increase by 2050 but in the global south, forested areas will decrease.
● Rate of forest loss has decreased from 9.5 million hectares per year in the 1990's to 5.5 million hectares per year in 2010-15.
● The eight countries with the largest forested areas are: Russia, Brazil, China, Canada, USA, DRC, Australia and Indonesia
● Brazil has the most carbon stored on land and the most extensive deforested area
. ● China has the largest amount of afforested area
. ● Net Primary Productivity (NPP) refers to the amount of carbon absorbed by forests. For tropical forests it is positive all year round, but deciduous forests, have a negative NPP in winter, but across the whole year their NPP is positive
SOIL CAPASITY TO STORE CARBON
Soils store between 20-30% of the world’s carbon. The amount of CO2 sequestered or emitted depends on local conditions. In arid and semi-arid soils are the most important store. Any loss by a plant to the ground means that some carbon will transfer to the soil. Soil microbes break down plants release carbon to the atmosphere. After organisms die, thousands of compounds in soil are decomposed. The most long-term process is the formation of Humus, it has a dark and rich colour and 60% of it contains carbon.
FACTORS EFFECTING
Climate – this affects the rate of plant growth and microbial activity. Decomposition occurs at a fast rate in places with higher temperatures and rainfall.
▪ Soil type – Clay rich soils contain more carbon than sandy soils.
▪ Use of soils – Land use, cultivation and disturbance can affect how much carbon can be held.
If plant residue is added to the soil at faster rate than soil organisms can convert it to CO2 , carbon will eventually be removed from the atmosphere and sequestered in the soil.